Why the water hasn't the right strenght to reach and to fall at the end of the road?
There are couple of issues with your file. 


Your pipe obstacle has wrong normals. The solidify modifier is applied only after the fluid simulation (see the order of modifiers), so the simulation is done using only the inner shell with flipped normals. Remove the fluid obstacle modifier, apply the solidify (check normals) and add the obstacle again.
Your inflow is highly suboptimal. Not only is it inside of the pipe, I would recommend an inflow plane altogether (if so, switch to shell)

The inflow has very weird inflow velocities They should point in negative y direction (and from some tests, they should have much smaller values).